The accepted wisdom is pretty much that there is no point buying either a dedicated DAC or amp unless your inbuilt DAC is **** (and yes, pretty much every audio device has a DAC)
I see some integrated audio implementations that measure very well in any scientific test - but if you listen to the same implementation side by side with something that has better routing of the traces, boutique capacitors instead of general purpose ones, etc. etc. it sounds noticeably dull side by side despite the measurements for SNR and THD, etc. etc. being close to identical between them.